Rhododendron plant named ‘ROBLEZA’

ABSTRACT

A new and distinct  Rhododendron  cultivar named ‘ROBLEZA’ is disclosed, characterized by upright fast growing, compact plants. Flowers are clear, bright red and occur as either single or double forms on the plant. Plants bloom Spring, Summer and Fall and exhibit good tolerance for both hot and cold conditions. The new cultivar is a  Rhododendron , suitable for ornamental garden purposes.

Latin name of the genus and species: Rhododendron hybrida.

Variety denomination: ‘ROBLEZA’.

BACKGROUND OF THE INVENTION

The new cultivar is a product of a planned breeding program by theinventor, Robert Edward Lee. The inventor's intention was to developRhododendron hybrid plants with re-blooming characteristics. This newvariety, hereinafter referred to as ‘ROBLEZA’, was discovered as aseedling, resulting from the crossing of Rhododendron ‘Red Slipper’,unpatented with the pollen parent Rhododendron ‘Arabesk’, unpatented.The cross resulting in the new variety occurred during 2004. The newvariety was selected by the inventor during November of 2007 at acommercial nursery in Independence, La.

After identifying the new variety as a potentially interestingselection, the inventor first organized propagation of ‘ROBLEZA’ byvegetative cuttings Fall of 2007 at the same commercial nursery inIndependence, La. The inventor continued controlled testing andpropagation, assessing stability of the unique characteristics of thisvariety. Multiple generations have been reproduced and have shown thatthe unique features of this cultivar are stable and reproduced true totype.

SUMMARY OF THE INVENTION

The cultivar ‘ROBLEZA’ has not been observed under all possibleenvironmental conditions. The phenotype may vary somewhat withvariations in environment such as temperature, day length, and lightintensity, without, however, any variance in genotype. The followingtraits have been repeatedly observed and are determined to be the uniquecharacteristics of ‘ROBLEZA’ These characteristics in combinationdistinguish ‘ROBLEZA’ as a new and distinct Rhododendron cultivar:

-   -   1. Unique Spring, Summer, and Fall blooming.    -   2. Clear red flowers.    -   3. Upright growth habit.    -   4. Tolerant of both warm and cold environmental conditions.    -   5. Single and semi-double flower forms both present on plant.    -   6. Very good foundation plant.    -   7. Hardy to Zone 6.    -   8. Uniform, globular plant shape.

COMPARISON TO PARENT VARIETY

‘ROBLEZA’ is similar in most horticultural characteristics to the seedparent Rhododendron hybrid ‘Red Slipper’. Plants of the new cultivar‘ROBLEZA’ however differ in the following:

-   -   1. The new variety has a clearer red flower.    -   2. The new variety blooms more consistently over three seasons.    -   3. Plants of the new variety are more compact.

‘ROBLEZA’ is similar in most horticultural characteristics to the pollenparent Rhododendron hybrid ‘Arabesk’. Plants of the new cultivar‘ROBLEZA’ however differ in the following:

-   -   1. ‘ROBLEZA’ produces single and semi-double flowers, flowers of        ‘Arabesk’ are always single.    -   2. The new variety has a brighter red flower.    -   3. The new variety blooms more consistently over three seasons.

COMMERCIAL COMPARISON

‘ROBLEZA’ can be compared to the commercial variety Rhododendron hybrid‘Conlef’ U.S. Plant Pat. No. 10,579. Plants of the new cultivar‘ROBLEZA’ are similar to plants of ‘Conlef’ in most horticulturalcharacteristics, however, plants of the new cultivar ‘ROBLEZA’ differ inthe following:

-   -   1. ‘Robleza’ has red flowers, ‘Conlef’ has red/pink flowers.    -   2. Plants of ‘Robleza’ are more compact than plants of ‘Conlef’.

‘ROBLEZA’ can be compared to the commercial variety Rhododendron hybrid‘Roblez’ U.S. Plant Pat. No. 28,279. Plants of the new cultivar‘ROBLEZA’ are similar to plants of ‘Roblez’ in most horticulturalcharacteristics, however, plants of the new cultivar ‘ROBLEZA’ differ inthe following;

-   -   1. ‘Robleza’ has lighter red flowers than ‘Roblez’.    -   2. Plants of ‘Robleza’ are more upright than plants of ‘Roblez’.    -   3. Foliage of ‘Robleza’ is consistently green in the Winter,        foliage of ‘Roblez’ can turn bronze in Winter.    -   4. Flower form of the new variety is single, flower form of        Robleza is semi-double.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying photograph in FIG. 1 illustrates in full color atypical plant of ‘Robleza’ in a 3 gallon pot.

FIG. 2 illustrates a close up of typical flowers of the new variety.

The photographs were taken using conventional techniques and althoughcolors may appear different from actual colors due to light reflectanceit is as accurate as possible by conventional photographic techniques.

DETAILED BOTANICAL DESCRIPTION

In the following description, color references are made to The RoyalHorticultural Society Colour Chart 2007 except where general terms ofordinary dictionary significance are used. The following observationsand measurements describe ‘ROBLEZA’ plants grown outdoors in Loxley,Ala. Plants are approximately 2 years old, in a 3 gallon nurserycontainer. Measurements and numerical values represent averages oftypical plant types.

-   Botanical classification: Rhododendron hybrida ‘ROBLEZA’.

PROPAGATION

-   Typically by semi-hardwood cuttings in Spring and Summer.-   Root description: Fine, fibrous young roots, well branched. Colored    near RHS Grey-Brown 199A.

PLANT

-   Growth habit: Compact, upright, globular shrub.-   Height: Approximately 45 cm to top of foliar and flowering plane.-   Growth rate: Rapid.-   Plant spread: Approximately 45 cm.-   Branching characteristics: Well branched, approximately 4 to 5    primary branches from the center of the plant. Branches occur at    approximately 15° to 45° angles. Each primary branch has 4 to 8    lateral branches.-   Primary branches:-   Length of primary branches: Average 19 cm.-   Diameter of primary branches: Approximately 0.6 cm.-   Primary branch strength: Very strong, flexible and difficult to    break.-   Primary branch color: Young primary branches near RHS Yellow-Green    144C; oldest branches become woody, colored near Brown 200B.-   Primary branch texture: Immature growth hirsute. Older growth scaly,    hirsute.-   Lateral branches:-   Number of lateral branches: Approximately 4 to 8 per primary branch.-   Length of lateral branches: Average 9 cm.-   Diameter of lateral branches: Average 0.4 cm.-   Lateral branch strength: Very strong, flexible.-   Lateral branch color: Immature branches near RHS Greyed-Red 180A,    turning, Yellow-Green 144C.-   Lateral branch texture: Hirsute.-   Internode length: Average 1.0 to 1.5 cm.-   Age of plant described: Approximately 2 years.

FOLIAGE

-   Leaf:    -   -   Type.—Simple.        -   Arrangement.—Alternate.        -   Average length.—Average range 3.5 to 4.8 cm.        -   Average width.—Average range 2.1 to 2.7 cm.        -   Shape of blade.—Obovate.        -   Apex.—Mucronate.        -   Base.—Broad attenuate.        -   Attachment.—Stalked.        -   Margin.—Entire.        -   Texture of top surface.—Pubescent. Hairs appressed.        -   Texture of bottom surface.—Pubescent. More hairs present            along main vein and margin.        -   Color.—Young foliage upper side: Near RHS Yellow-Green 144B.            Young foliage under side: Near RHS Yellow-Green 144C. Mature            foliage upper side: Near RHS Green 139A. Mature foliage            under side: Near RHS Green 137D.        -   Venation.—Type: Pinnate. Venation color upper side: Near RHS            Yellow-Green N144A. Venation color under side: Near RHS            Green 138B.        -   Petiole.—Length: About 0.6 cm. Diameter: About 0.15 cm.            Color: Upper Surface: Near RHS Yellow-Green 144D. Lower            Surface: Near RHS Yellow-Green N144D.

FLOWER

-   Bloom period: Plants begin flowering in the Spring, and continue to    produce flowers throughout Summer and Fall.-   Flower:    -   -   Arrangement.—Axillary clusters of single or semi-double,            perfect, open funnel shaped individual flowers. Typically 3            to 5 flowers per cluster.-   Inflorescence:    -   -   Height.—Average 12.0 cm.        -   Diameter.—Average 14.0 cm.-   Peduncle:    -   -   Length.—Average range 4 to 7 cm.        -   Diameter.—0.3 cm.        -   Color.—Near RHS Yellow-Green 144C.        -   Texture.—Densely pubescent.        -   Aspect.—Straight. Angle of attachment, approximately 15 to            35° angle from stem.-   Flowers:    -   -   Length.—Average 4.8 cm.        -   Diameter.—Average 6.2 cm.        -   Facing direction.—Outwardly and upwardly facing.        -   Persistent or self-cleaning.—Petals self-cleaning.        -   Fragrance.—Very faint.-   Tube:    -   -   Tube length.—Approximately 1.7 cm.        -   Tube width a widest point.—Approximately 1.3 cm.        -   Tube width and narrowest point.—Approximately 0.5 cm.-   Petals:    -   -   Unfused petal segments.—        -   Length.—Approximately 2.9 cm.        -   Width.—Approximately 3.7 cm        -   Apex.—Blunt, rounded with shallow, irregular lobes.        -   Shape of petal.—Unfused portion, obovate.        -   Petal margin.—Entire. Aspect very slightly undulating.        -   Petal arrangement.—Overlapping, bilateral symmetry            dissecting bottom petal. Petals fused approximately ⅓ fused            from base.        -   Petal number.—5, occasionally 3 to 5 petaloids present,            forming a semi-double flower.        -   Petal texture.—Smooth.-   Color:    -   -   Upper surface at first opening.—Near RHS Red 45C.        -   Under surface at first opening.—Near RHS Red 45C.        -   Inner surface at maturity.—Near RHS Red 45B, 3 upper petals            dotted with Red 53A.        -   Outer surface at maturity.—Near RHS Red 45C.        -   Upper surface at fading.—Near RHS Red 46C, 3 upper petals            dotted with Red 53A.        -   Under surface at fading.—Near RHS Red 46C.-   Bud:    -   -   Shape.—Elliptic.        -   Length.—3.5 cm.        -   Diameter.—1.4 cm.        -   Color.—Near RHS Red 45B.-   Calyx/sepals:    -   -   Quantity per flower.—5 sepals.        -   Shape.—Narrow deltate.        -   Length.—0.9 cm.        -   Width.—0.4 cm.        -   Apex.—Acute.        -   Base.—Fused.        -   Margin.—Entire.        -   Texture.—Highly pubescent.        -   Color.—Inner Surface: Near RHS Yellow-Green 145A. Outer            Surface: Near RHS Yellow-Green 145A.

REPRODUCTIVE ORGANS

-   Stamens:    -   -   Number.—5 full stamens, 5 staminoidal structures,            approximately 50% of the size of the full stamens.        -   Length.—2.8 cm.        -   Width.—0.1 cm.        -   Color.—Near RHS Red-Purple 58B.        -   Anthers.—Length: Approximately 0.3 cm. Color: Near RHS Red            53A. Pollen: Not observed.-   Pistil:    -   -   Number.—1.        -   Length.—4.9 cm.        -   Style.—Length: Average 3.9 cm. Color: Near RHS Red 53D.        -   Stigma.—Globular, colored near Red 46C.        -   Ovary.—Sericeous texture. Approximately 0.3 cm in diameter.            Colored near Yellow-Green 145A.

OTHER CHARACTERISTICS

-   Disease and pest resistance: Not observed to be susceptible nor    resistant to normal diseases and pests of Rhododendron.-   Temperature tolerance: USDA Zone 6 though Zone 9.-   Fruit/seed production: Not observed to date.

What is claimed is:
 1. A new and distinct cultivar of Rhododendron plantnamed ‘ROBLEZA’ as herein illustrated and described.